Trolley-wire insulator



(No Model.) 2 Sheets-Sheet 2. H. H. LUSGOMB. TROLLEY WIRE INSULATOR.

No. 512,888. Patented Jan. 16,1894.

UNITED STATES l PATENT OEEIcE.

HENRY HERBERT LUSCOMB, OF HARTFORD, CONNECTICUT.

TROLLEY-WlRE INSULATOR.

SPECIFICATION forming part of Letters Patent No. 512,888, dated January 16, 1894.

Application tiled October 18, 1893. Serial No. 438,494. (No model.)

To @ZZ whom it may concern,.-

Be it known that I, HENRY HERBERT LUs- MB, a citizen of the United States, residing at Hartford, in the county of Hartford and State of Connecticut, have invented certain new and useful Improvements in Insulators, of which the following is a specification, reference being had therein to the accompanying drawings.

My invention has for its object to provide an improved electrical insulator and it relates more particularly to insulators such as are employed for insulating and supporting overhead conductors for electric railways.

My invention consists in an insulator of improved construction hereinafter more fully set forth and the novel features of which are pointed out in the claims which are appended hereto and made a part hereof.

The invention will be fully understood from the following description reference being had to the accompanying drawings, in which- Figure l is a view of my insulator in elevation, partially broken away for greater clearness. Fig. 2 is a plan view thereof. Fig. 3 is aplan view of the yokehaving arms by means of which connection is made with the span wire. Fig. t is an edge view of the same. Fig. 5 is a section thereof on line 5-5 Fig. 3. Fig. 6 is a section of the case or bell of the insulator detached. Figs. '7 and 8 are views in plan and side elevation of the connection hereinafter referred to. Figs. 9 and l0 are similar views of the caphereinafterreferred to.

In insulators of the class referred to it is desirable that the interior parts should be thoroughly protected from the entrance of moisture; that the device. should be strong and durable and of high insulative quality; that the downwardlyproj ecting portions nearest the line of the trolley wire should be so constructed as to withstand a blow such as might be given by a misplaced trolley-wheel without injury to the insulator; that the insulator should be so constructed as to be readily removed and replaced, if desired, without the necessity of removing any other portions of the construction, and that the ear may be attached and secured in place to coincide with the line of the trolley wire regardless of the angle at which the trolley wire crosses the span wire. These objects I have endeavored to obtain in the construction which embodies my present invention and I will now proceed to describe the same having reference to the accompanying drawings.

The metallic case of the insulator is shown at l, and consists of a body portion and a skirt or flaring downwardly projecting part which is adapted to shed moisture and to otherwise protect the insulator. An inwardly projecting flange 2 located at the base of the body of the body portion serves to retain the portions of the insulator within the bell in place. The body of the bell is provided exteriorly with an annular groove 3 which re` ceives the yoke 4. to which the arms 5 are secured. The arms 5 are provided with upwardly projecting curved portions 6 of the usual form at their extremities to receive the span wire, said wire passing around one side of the yoke portion 4 in a groove provided therein to receive said span wire. It will thus be observed that the span wire does not touch the bell or case l of the insulator. The top of the bell or case is provided witha series, preferably four, of upwardly projecting portions 7, which are adapted to be bent over the cap S when placed Within the top of the case, and serve to retain said cap in place. The interior of the skirt of the case is provided with a series of annular grooves or notches shown at 9 and the lower edge 10 of said skirt is adapted to be bent inwardly upon the layer or mass of composition which is employed to cover the interior of the skirt and to close the jointaround the connection 1l. The notches 9 and the inwardly turned edge 10 serve to secure in place the layer or mass of composition which covers the interior of the skirt. The connection 11 consists of a bolt having a head of irregular shape and having its downwardly projecting end screw-threaded in order that it may be screwed into a threaded socket in the ear which connects with the trolley wire. The shank of the connection projects downwardly through the hole in the bottom of the case and is of less diameter than said hole. Before the connection ll is placed within the case, a series of sheets of mica 14E which are cut to proper shape to iit the interior of the case are strung on said bolt underneath the head thereof. The connection ll is then IOO placed within the case and another series of sheets of mica 15 which are also shaped to fit the interior of the case are placed on top of the said connection. The cap 8 is then placed within the case on top of the mica 15 and the upwardly projecting portions 7 are bent over the edges of the cap, compressing the parts within the case and holding them firmly in place. For the purpose of filling the space between the head of the connection and the adjacent wall of the case, a series of holes 25 are provided in the iiange 2 and by means of a punch or similar instrument inserted through these holes openings are made through the mica 14 thus opening aseries of passages into the space referred to between the head of the connection and the wall of the case. A mass of insulating composition which is prepared in a plastic condition and which will set and harden is thenmforced through the holes filling the space aroundthe head of the connection and serving to insulate the samejrom the case. This composition also lls the holes leading to the said space around the head of the connection and is continued in the form pf a layer around the interior of the skirt. Before the composition hardens the edge 10 of the skirt is bent inwardly as shown in Fig. 1 onto the composition, thus serving to retain it securely 1n place and also serving to protect it thoroughly from an accidental blow from the trolley. The layer of composition will also extend up to the shank of the connection 11 and into the space between the edge of the iiange 2 and lsaid shank. This layer of composition is shown at 16. Any of the well-known insulating compositions which may be used in a plastic condition `and will then set andharden may be employed.

In order to finish the top of the insulator and prevent the lodgment of moisture or the like around the top of the cap 8, I lill the space around the turned over ends of theportion 7 with a mass of insulating composition 17 which may be of the same composition which is employed for the interior of the skirt. As it is desirable that the connection 11 shall not twist or turn relatively to the case 1, the head of the connection is preferably of irregular shape or provided with vertical notches 26 or grooves and the interior of the case is roughened or provided with corresponding vertical grooves 27 or projections so that when the plasticcomposition which surrounds the head of the connection hardens the oon- .nection will be rigid relatively to the case. The top 18 of the cap 8 is shaped to receive a wrench as shown so that the insulator may be turned to screw the connection into the ear. The cap 8 is also provided with ribs 22 between which are spaces which receive the turned over ends of the projections 7. In this way the cap 8 is locked relatively to the case 1 and cannot be rotated or moved within the case relatively thereto so that these turned over projections 7 not only serve to hold the cap in place vertically within the case but also serve to prevent its rotation relatively to the case.

The yoke 4 is provided with preferably two inwardly projecting parts 19 which are adapted to engage with the annular groove 3 in the body of the same. At one side of the yoke a boss or projection 20isprovided through which a threaded hole passes to receive a set screw 21. The yoke is of such a size that when the set screw 21 is withdrawn it may be passed over the case 1 into the groove 3. The set screw 21 is then inserted and screwed in until its inner end bears in the groove 3 when the arms and yoke are firmly secured to vthe insulator. As will be clear by loosening the set screw the insulator may be turned relatively to the arms and both the arms and the insulator may be adjusted to coincide with the position of the span and trolley wires. If the insulator requires to be replaced it is'only necessary to withdraw the set screw 21, free the insulator from the yoke and arms and unscrew it from the ear; another insulator may then be inserted and the parts again secured without disturbing any other portions of the construction.

What I claim is- 1. An insulator comprising a case, a connection within said case, insulating material surrounding said connection and insulating the same from said case, a cap within said case having recesses therein and projections on said case which are bent over said cap and received in the said recesses therein, substantially as set forth.

2. An insulator comprising a case havinga skirt thereon, a connection within said case, insulating material surrounding said connection and insulating the same from said case and a layer of insulating material on the inner surface of said skirt, said skirt having the edge thereof turned inwardly over the edge of the layer of insulating material whereby said layer is protected from injury substantially as set forth.

3. An insulator comprising a case, a connection within said case, insulating material surrounding said connection and insulating the same from said case, a cap within said case and means for locking said cap rigidly to said case, the proximate portions of said connection and 'said case being of irregular shape whereby the connection is 4prevented from rotating within the said case, substantially as set forth.

4. An insulator comprising acase having an exterior annular groove, a connection within said case, insulating material interposed between said connection and said case, and means for `securing said parts together in combination with a yoke and means for securing said yoke to its support, said yoke having projections engaging saidv annular groove to secure said yoke andcase'together, substantially asset forth.

5. An insulator comprisinga casel having TOO an exterior annular groove, a connection withmay be rigidly secured in said annular groove,

in said case, insulating material interposed substantially as set forth. 1o between said connection and said ease, and In testimony whereof I affix my signature in means for securing said parts together in presence of two witnesses.

combination with a yoke and means for se- HENRY HERBERT LUSCOMB. curing said yoke to its support, said yoke hav- Witnesses: ing proj eetions engaging said annular groove .VM. A. MACLEOD,

and having a set screw by means of which it ROBT. VALLACE. 

